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    <h3>Editing: TranslatorBag.php</h3>
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/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier &lt;fabien@symfony.com&gt;
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Symfony\Component\Translation;

use Symfony\Component\Translation\Catalogue\AbstractOperation;
use Symfony\Component\Translation\Catalogue\TargetOperation;

final class TranslatorBag implements TranslatorBagInterface
{
    /** @var MessageCatalogue[] */
    private array $catalogues = [];

    public function addCatalogue(MessageCatalogue $catalogue): void
    {
        if (null !== $existingCatalogue = $this-&gt;getCatalogue($catalogue-&gt;getLocale())) {
            $catalogue-&gt;addCatalogue($existingCatalogue);
        }

        $this-&gt;catalogues[$catalogue-&gt;getLocale()] = $catalogue;
    }

    public function addBag(TranslatorBagInterface $bag): void
    {
        foreach ($bag-&gt;getCatalogues() as $catalogue) {
            $this-&gt;addCatalogue($catalogue);
        }
    }

    public function getCatalogue(string $locale = null): MessageCatalogueInterface
    {
        if (null === $locale || !isset($this-&gt;catalogues[$locale])) {
            $this-&gt;catalogues[$locale] = new MessageCatalogue($locale);
        }

        return $this-&gt;catalogues[$locale];
    }

    public function getCatalogues(): array
    {
        return array_values($this-&gt;catalogues);
    }

    public function diff(TranslatorBagInterface $diffBag): self
    {
        $diff = new self();

        foreach ($this-&gt;catalogues as $locale =&gt; $catalogue) {
            if (null === $diffCatalogue = $diffBag-&gt;getCatalogue($locale)) {
                $diff-&gt;addCatalogue($catalogue);

                continue;
            }

            $operation = new TargetOperation($diffCatalogue, $catalogue);
            $operation-&gt;moveMessagesToIntlDomainsIfPossible(AbstractOperation::NEW_BATCH);
            $newCatalogue = new MessageCatalogue($locale);

            foreach ($operation-&gt;getDomains() as $domain) {
                $newCatalogue-&gt;add($operation-&gt;getNewMessages($domain), $domain);
            }

            $diff-&gt;addCatalogue($newCatalogue);
        }

        return $diff;
    }

    public function intersect(TranslatorBagInterface $intersectBag): self
    {
        $diff = new self();

        foreach ($this-&gt;catalogues as $locale =&gt; $catalogue) {
            if (null === $intersectCatalogue = $intersectBag-&gt;getCatalogue($locale)) {
                continue;
            }

            $operation = new TargetOperation($catalogue, $intersectCatalogue);
            $operation-&gt;moveMessagesToIntlDomainsIfPossible(AbstractOperation::OBSOLETE_BATCH);
            $obsoleteCatalogue = new MessageCatalogue($locale);

            foreach ($operation-&gt;getDomains() as $domain) {
                $obsoleteCatalogue-&gt;add(
                    array_diff($operation-&gt;getMessages($domain), $operation-&gt;getNewMessages($domain)),
                    $domain
                );
            }

            $diff-&gt;addCatalogue($obsoleteCatalogue);
        }

        return $diff;
    }
}
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